The invention relates generally to electronic switches using light actuated control. In particular, the invention relates to using metamaterial switches using metamaterial for switch actuation.
Reflectarrays are known to those skilled in the art of antenna designs as useful for reflecting an electromagnetic wave at various angles by electrically controlling the phase of the elements that make up the array. A phased array can be used to control the direction of electromagnetic waves. Usually the array elements are progressively phased with a uniform amplitude excitation.
By controlling the phase of individual radiators within the array, a narrow electromagnetic beam with well-defined direction can be formed. By dynamically changing the relative phase and amplitude in ways known to those skilled in the art of antenna phased array design, the beam can be steered. See: A. J. Fenn, D. H. Temme, W. P. Delaney, and W. E. Courtney “The Development of Phased-Array Radar Technology,” LINCOLN Laboratory Journal, 12, 321 (2000); and D. G. Berry, R. G. Malech, and W. A. Kennedy, “The Reflectarray Antenna”, IEEE Transactions on Antennas and Propagation 11, 645 (1963) into different directions. Often, the elements are designed to radiate at a given frequency or over a range of frequencies.
Phase shifters are electrically controlled and can be expensive due to the complicated electronic circuits required thereby. Each antenna array is often composed of hundreds or thousands of phase shifters. These types of devices can be affected by electromagnetic interference (EMI) between the many shifters. EMI often complicates the designs and increases costs of manufacture and operation.
A metamaterial is a metallic or semiconductor substance whose properties depend on engineered structures at the sub-wavelength scale rather than on the composition of the atoms themselves. Certain metamaterials bend visible light rays in the opposite sense from traditional refractive media K. A. Boulais et al. “Tunable split-ring resonator for metamaterials using photo-capacitance of semi-insulating GaAs” Applied Physics Letters 93, 043518 (2008). Photo-capacitors respond to variation in light intensity primarily, but also to variation in light frequency, by changing their capacitance.